Multiplicity Fluctuations and Bose-einstein Correlations in Dis at Hera

Various aspects of multihadron production can be revealed through multiplicity fluctuations and particle correlations studies. The fluctuations are sensitive to soft particle dynamics and their measurements allow to test perturbative QCD 1 and local parton hadron duality (LPHD) hypothesis . In BEC studies , the correlation function gives information about the shape, size and lifetime of the boson emitter source. In the fluctuations studies, the method of normalized factorial moments, Fq, was used . The moments of order q were calculated by counting n, the number of charged particles in a restricted region of phase space, Ω: Fq(Ω) = < n > −q < n(n− 1) . . . (n− q + 1) >, (1)